N-2-nitrobutyl morpholine and 2,2-dibromo-3-nitrilopropionamide as a slime control composition

ABSTRACT

The present invention relates to certain processes and compositions useful for inhibiting the growth of slime in water and, in particular, water used for industrial purposes; for example, in the manufacture of pulp paper, in the manufacture of paper, in cooling water systems and in effluent water treatment. The novel processes and compositions of the present invention are processes or mixtures which show unexpected synergistic activity against microorganisms, including bacteria, fungi and algae, which produce slime in aqueous systems or bodies which are objectionable from either an operational or aesthetic point of view. Specifically, the invention is directed to the use of compositions comprising a combination of N-2-nitrobutyl morpholine and 2-2-dibromo-3-nitrilopropionamide.

United States Patent Shema et al.

N-Z-NITROBUTYL MORPHOLINE AND 2,2-DIBROMO-3-NITRILOPROPIONAMIDE AS ASLIME CONTROL COMPOSITION Inventors: Bernard F. Shema, Glenside; RobertH. Brink, Jr., Doylestown; Paul Swered, Philadelphia, all of Pa.

U.S. Cl. 424/248; 210/64; 252/180 Int. Cl. AOIN 9/22 Field of Search252/180, 106, 403;

References Cited UNITED STATES PATENTS 9/1962 Bennett et al. 252/855 D2/1970 Schmidt et al..... 424/267 1/1971 Toepfl et al. 260/465.4 5/1972Shema et al. 210/64 July 29, 1975 Primary Examiner-Benjamin R. PadgettAssistant Examiner-Deborah L. Kyle Attorney, Agent, or FirmAlexander D.Ricci 5 7 ABSTRACT The present invention relates to certain processesand compositions useful for inhibiting the growth of slime in water and,in particular, water used for industrial purposes; for example, in themanufacture of pulp paper, in the manufacture of paper, in cooling watersystems and in effluent water treatment. The novel processes andcompositions of the present invention are processes or mixtures whichshow unexpected synergistic activity against microorganisms, includingbacteria, fungi and algae, which produce slime in aqueous systems orbodies which are objectionable from either an operational or aestheticpoint of view. Specifically, the invention is directed to the use ofcompositions comprising a combination of N-2-nitrobutyl morpholine and2-2-dibromo-3-nitrilopropionamide.

8 Claims, No Drawings N-Z-NITROBUTYL MORPHOLINE AND2,2-DIBROMO-3-NITRILOPROPIQNAMIDE AS A SLIME CONTROL COMPOSITIONBACKGROUND OF THE INVENTION The formation of slime by microorganisms isa problem which attends many systems. For example, lagoons. lakes,ponds, pools, and such systems as cooling water systems and pulp andpaper mill systems all possess conditions which are conducive to thegrowth and reproduction of slime-forming microorganisms. In bothonce-through and recirculating cooling systems, for example, whichemploy large quantities of water as a cooling medium, the formation ofslime by microorganisms is an extensive and constant problem.

Airborne organisms are readily entrained in the water from coolingtowers and find this warm medium an ideal environment for growth andmultiplication. Aerobic and heliotropic organisms flourish on. the towerproper while other organisms colonize and grow in such areas as thetower sump and the piping and passages of the cooling system. Such slimeserves to deteriorate the tower structure in the case of wooden towers.In addition, the deposition of slime on metal surfaces promotescorrosion. Furthermore, slime carried through the cooling system plugsand fouls lines, valves, strainers, etc., and deposits on heat exchangesurfaces. In the latter case, the impedance of heat transfer can greatlyreduce the efficiency of the cooling system.

In pulp and paper mill systems, slime formed by microorganisms is alsofrequently and, in fact, commonly encountered. Fouling or plugging byslime also occurs in the case of pulp and paper mill systems. Of greatersignificance, the slime becomes entrained in the paper produced to causebreakouts on the paper machines with consequent work stoppages and theloss of production time or unsightly blemishes in the final productwhich results in rejects and wasted output. The previously discussedproblems have resulted in the extensive utilization of biocides incooling water and pulp and paper mill systems. Materials which haveenjoyed widespread use in such applications include chlorine,organo-mercurials, chlorinated phenols, organobromines; and variousorgano-sulfur compounds. All of these compounds are generally useful forthis purpose but each is attended by a variety of impediments. Forexample, chlorination is limited both by its specific toxicity forslime-forming organisms at economic levels and by the ability ofchlorine to react which results in the expenditure of the chlorinebeforeits fullbiocidal function may be achieved. Other biocides areattended by odor problems and hazards in respect to storage, use orhandling which limit their utility. To date, no one compound or type ofcompound has achieved a clearly established predominance in respect tothe applications discussed. Likewise, lagoons, ponds, lakes and evenpools, either used for pleasure purposes or used for industrial purposesfor the disposal and storage of industrial wastes, become, during thewarm weather, besieged by slime due to microorganism growth andreproduction. In the case of the recreational areas, the problem ofinfection, etc., is obvious. In the case of'in -dustrial storage ordisposal ofindustrialmaterials, the

microorganisms cause additional problems which must be eliminated priorto the materials use .or the waste is treated for disposal.

Naturally, economy is a major consideration in respect to all of thesebiocides. Such economic considerations attach to both the cost of thebiocide and the expense of itsapplication. The cost-performanceindex ofany biocide is derived from the basic cost of the material, itseffectiveness per unit of weight, the duration of its biocidal orbiostatic effect in the system treated, and the ease and frequency ofits addition to the system treated. To date, none of the commerciallyavailable biocides have exhibited a prolonged biocidal effect. Instead,their effectiveness is rapidly reduced as the result of exposure tophysical conditions such as temperature. association with ingredientscontained by the system toward which they exhibit an affinity orsubstantivity', etc., with a resultant restriction or elimination oftheir biocidal effectiveness. i

Asa consequence. the use of such biocides involves their continuous orfrequent addition to systems to be treated and their addition to aplurality of points or zones 'in the systems to be treated. Accordingly,the cost of the biocide and the labor cost of such means of applying itare considerable. In other instances, the difficulty of access to thezone in which slime formation is experienced precludes the effective useof a biocide. For example, in a particular system there is no access toan area at which slime formation occurs and it may only be applied at apoint which is upstream in the flow system. However, the physical orchemicalconditions, e.g., chemical reactivity, thermal degradation,etc., which exist between the point at which the biocide may be added tothe system and the point at which its bio cidal effect is desired renderthe effective use of a biocide impossible.

Similarly, in a system experiencing relatively slow flow, such as apaper mill, if a biocide is added at the beginning of the system, itsbiocidal effect may be completely dissipated before it has reached allof the points at which this effect is desired or required. As aconsequence, the biocide must be added at a plurality of points, andeven then a graduated biocidal effect will be experienced between onepoint of addition to the system and the next point downstream at whichthe biocides may be added. In addition to the increased cost ofutilizing and maintaining plural feed points, gross ineconomies inrespect to the cost of the biocide are experienced. Specifically, ateach point of addition, an excess of the biocide is added to the systemin order to compensate for that portion of the biocide which will beexpended in reacting with otherconstituents present in the system orexperience physicalchanges which im pair its biocidal activity.

It is an object of the present invention to provide methods andcompositions for controlling slimeforming microorganisms in aqueoussystems such as cooling water systems and pulp and paper mill systems,and for controlling slime formation or microorganism populations inaqueous bodies in general. Moreover, another object of the invention isthe provision of methods and compositions for controlling slime formingmicroorganisms in any aqueous system which is conducive to the growthand reproduction of microorganisms and, in particular, cooling water andpaper and pulp mill systems which employ a combination ofN-2-nitrobutyl-morpholine and 2-2-dibromo-3- nitrilopropionamide. p

In practice of the invention, the combination is added to theparticular'system being treated; for example,

cooling water systems, paper and pulp mill systems, pools, ponds,lagoons, lakes, etc., in a quantity adequate to control theslime-forming microorganisms which are contained by, or which may becomeentrained in, the system which is treated. It has been found that suchcompositions and methods control the growth and occurrence of suchmicroorganisms as may populate these particular systems.

N-2-nitrobutyl-morpholine is commercially as Vancide 40 of theVanderbilt Chemical Company, and 2- 2-dibromo-3-nitrilopropionamide isavailable as an anti-microbial agent, Dow XD7287L of The Dow ChemicalCompany, hereafter DBNP.

As earlier stated, the inventive compositions are comprised of thelatter compounds. either compound being present in such a quantity as toimpart a synergistic behavior to the composition as a whole, the weightratio of the morpholine to the DBNP ranging from about 5:95 to about95:5. When these two ingredients are mixed, the resulting mixturespossess a high degree of slimicidal activity which could not have beenpredicted beforehand from the known activity of the individualingredients comprising the mixture. Accordingly, it is thereforepossible to produce a more effective slime-control agent than haspreviously been available. Because of the enhanced activity of themixture, the total quantity of the biocide required for an effec tivetreatment may be reduced. In addition, the high degree of biocidaleffectiveness which is provided by ingredients working alone inconcimitantly prepared agar medium plates. Synergism was determined bythe method described by F. C. Kull, P. C. Eisman, H. D. Sylwestrowiczand R. L. Mayer, APPLIED MICROBI- OLOGY, 9, 5384l, (1946), and therelationships,

l is synergism =1 is antagonism and =1 is additivity where,

Q Quantity of Compound A, acting alone, producing an end point Q,Quantity of Compound B, acting alone, producing an end point Q, Quantityof Compound A, in the mixture, producing an end point OH Quantity ofCompound B, in the mixture, producing an end point For mixtures ofCompounds A and B, and for Compound A and Compound B acting alone, thefollowing results were observed. Summary of synergistic activity ofvarying percentages of Compound A and Compound B:

SYNERGISTIC COMBINATION Compound A: N-Z-nitrobutyl-morpholine CompoundB: DBNP TABLE I TEST ORGANISM AEROBACI' ER AEROGENES each of theingredients may be exploited without use of the higher concentrations ofeach.

To demonstrate the synergism which is provided by the inventivecombinations of compounds, the data as set forth in the Table below wasdeveloped.

EXAMPLE 1 The mode of establishing the synergistic behavior of thecompositions of the present invention is a widely used and anindustrially acceptable procedure. Although it is believed that theabove is sufficient in explaining the procedure, for a furtherdescription thereof reference can be made to US Pat. No. 3,231,509 andits file history where data of this nature was considered to beacceptable. Moreover, the article by Kull et al. published in APPLIEDMICROBIOL- OGY, 9, 53854l, will furnish additional information in thisregard. a

For the testing to ascertain synergistic behavior, Aerobacter aerogeneswas favored since this microorganism is found to exist and found to bemost troublesome in pulp and paper producing processes, as well as incooling towers. Moreover, this microorganism is difficult to controland/or kill and accordingly its existence does give rise to troublesomeslime. In view of the foregoing, it can then be appreciated that sinceAerobacter aerogenes is prevalent in most slime-affected systems andsince this microorganism is difficult to control or kill, that oncecontrol of this microorganism is maintained, then for all practicalpurposes the total microorganism population with its different typesisconsidered controlled. I i

When the inventive compositions are employed in the treatment of coolingor paper mill water, they are preferably utilized in the form ofrelatively dilute solutions or dispersions. For example, a preferredsolution comprises between 5 to 65 percent byrweight of the synergisticcombination in admixture with various solvents and solubilizing agents.i

Surfactants such as the alkylaryl polyether alcohols, polyetheralcohols, alkyl benzene sulfonates and sulfates, and the like, may alsobe employed to enhance the dispersibility and stability of theseformulations. The foregoing solutions of the biocidal compositions areutilized in order to insure the rapidand uniform dispersibility of thebiocides within the industrial water which is treated. It has been foundthat either aqueous or non-aqueous solvents are generally suitable inthe preparation of compositions of the invention. For example, organicsolvents such as methyl cellosolve and aliphatic and aromatichydrocarbons, e.g., kerosene, can be used quite successfully. Based uponthe synergism study as outlined above, it was ascertained. that in thetreatment of paper mill and cooling water, effective biocidal action isobtained when the concentration ,or treatment level of the combinationoradmixture of biocides is between 0.5 parts per million to 1,000 partsper million, and preferably between 1 and 100 parts per million, basedupon the total content of the system treated, such as the total quantityof cooling water or paper mill water.

The compositions may also be utilized for the preservation of slurriesand emulsions containing carbohydrates, proteins, fats, oils, etc.Dosage levels for this purpose range in the vicinity of 0.01 to 5percent.

The compositions of the invention which can be prepared by merelycombining the respective ingredients and mixing thoroughly at standardconditions may be fed continuously to the treated system, e.g., by meansof a metered pump, or may be fed periodically at intervals calculated tocontrol the growth of slime-forming organisms in the system. Naturally,in the treatment of cooling water the feeding of the inventivecompositions must be designed to compensate for blowdown in thosesystems which employ that expedient.

As would be expected, the inventive composition may be added to thecooling water or paper and pulp mill systems at any convenient point.Naturally, in once-through or non-circulating systems, the compositionmust be added upstream from the point or points at which microorganismcontrol is desired. In circulating systems or pulp and paper systems,the composi tions may be added at any point provided that the time lapseand the conditions experienced between point of addition and the pointat which the effect of the composition is experienced are not so drasticas to result in the neutralization of the effect of the composition.

SLIME CONTROL EFFECTIVENESS The. inventive methods and materials weretested with respect to their performance in the control of slimeformation in industrial systems. In this test an industrialrecirculating water was obtained from a system which was currentlyexperiencing problems in respect to the formation of slime bymicroorganisms. Such tests do not demonstrate the efficiency of thebiocideemployed with respect to specific species of microorganisms butinstead supply a practical demonstration of the efficacy of the'biocidetested in relation to those communities of microorganisms which haveevidenced their ability to form slirne in actual industrial systems.

In testing of recirculating-water samples, a substrate evaluation wasemployed. In such testing, identical portions of water samples aretreated with varying concentrations of biocide and two portions are leftuntreated to-serve as controls. The control portions are plated fortotal count at the beginning of biocide. treatment and all portions areplated for total count at some suitable time period(s)'after beginningbiocide treatment. Using thecounts obtained from the platings, thepercentage kill (based on the initial control count) may be calculated.In the following example,.the water sample was taken from a papermachine headbox sample from a paper mill located in northwestern UnitedStates.

For the'purposes of comparison, a composition of this invention wasevaluated with two recognized commercial biocides.

EFFICACY RELATIVE TO FUNGI In order to ascertain whether in fact theinventive compositions were effective in controlling fungi, evaluationswere made following the procedure described by Shema et al., JOURNAL FORTHE TECHNICAL ASSOCIATION OF THE PULP AND PAPER INDUS- TRY. 36, 2OA3OA,I953. The described procedure generally entails incorporating thebiocide under test in a nutrient substrate such as agar, malt, etc., andpouring the resulting medium in a Petri dish and allowing the medium tosolidify. A button of fungus inoculum is placed on the surface of thesolidified medium and the medium is incubated for a period of 14 days.After the period, the diameter of the colony is measured and comparedwith the diameter of the button of inoculum originally placed upon thesurface. If there is no increase in the diameter, the growth of thefungus is considered to be completely inhibited and the treatment levelwhich effectuates this is considered the inhibitory concentration.

The fungi species utilized as the test microorganism to evaluate theefficacy of the present compositions were Penicillium expansum andAspergillus niger. The study revealed that the above 10 percent activecomposition of this invention inhibited the growth of Penicilliumexpansum at a treatment level of 300 ppm and 500 ppm completelyinhibited the growth of Aspergillus niger.

Bactericidal Effectiveness The bactericidal effectiveness ofa /1 mixtureofthe two components of this invention (60 percent active) isdemonstrated by the following data in which the inhibiting power isshown in comparison with a commercial biocide. Aerobacler aerogenes wasemployed as the test organism and a substrate technique was utilized.Specifically, the biocidal mixture was added in gradually increasingquantities to nutrient agar media which was then innoculated withAerobacter aerogenes. The preparation was then incubated for 48 hours.The below values indicate the quantity of biocide required to achievecomplete inhibition of the growth of the test organism.

Inhibition Biocide Materials quantity (ppm) 1. N-Z-nitrobutyl morpholine(50%) DBN P(l0%) 90 Inert (407:) 2. RX-38 30 ples taken from paper andpulp mill aqueous systems, the compositions and methods of the presentinvention are broadly applicable to the treatment of aesthetic waters aswell as industrial waters such as cooling waters which are plagued bydeposits formed by slime-forming organisms, or by the very presence ofsuch organisms.

Having thus described the invention, what is claimed 1. A compositionfor the control of Aerobacter aerogenes in aqueous systems comprisingN-Z-nitrobutyl morpholine and 2-2-dibromo-3-nitrilopropionamide. whereinthe weight ratio of the morpholine to the amide ranges from about 5:95to about :5 respectively.

2. The composition of claim 1 where said ratio is about 50:50.

3. A method for controlling the growth of Aerobacter aerogenes in anaqueous system which comprises adding to said system an effective amountof a composition comprised of N-2-nitrobutyl-morpholine and 2-2-dibromo-3-nitrilopropionamide, wherein the weight ratio of themorpholine to the amide ranges from about 5:95 to about 95:5respectively.

4. The method of claim 3 wherein said ratio is about 50:50.

5. The method of claim 3 wherein said composition is added to saidsystem in an amount of from about 0.1 to about 1,000 parts per by weightof said composition per million parts by weight of said aqueous system.

6. The method of claim 5 where said composition amount is from about 1to about parts per million of said aqueous system.

7. The method of claim 5 wherein the aqueous system is that of a coolingwater system.

8. The method of claim 5 wherein the aqueous system is that of a pulpand paper mill system.

1. A COMPOSITION FOR THE CONTROL OF AEROBACTER AEROGENES IN AQUEOUSSYSTEMS COMPRISING N-2-NITROBUTYL MORPHOLINE AND2-2-DIBROMO-3-NITRILOPROPIONAMIDE, WHEREIN THE WEIGHT RATIO OF THEMORPHOLINE TO THE AMIDE RANGES FROM ABOUT 5:95 TO ABOUT 95:5RESPECTIVELY.
 2. The composition of claim 1 where said ratio is about50:50.
 3. A method for controlling the growth of Aerobacter aerogenes inan aqueous system which comprises adding to said system an effectiveamount of a composition comprised of N-2-nitrobutyl-morpholine and2-2-dibromo-3-nitrilopropionamide, wherein the weight ratio of themorpholine to the amide ranges from about 5: 95 to about 95:5respectively.
 4. The method of claim 3 wherein said ratio is about50:50.
 5. The method of claim 3 wherein said composition is added tosaid system in an amount of from about 0.1 to about 1,000 parts per byweight of said composition per million parts by weight of said aqueoussystem.
 6. The method of claim 5 where said composition amount is fromabout 1 to about 100 parts per million of said aqueous system.
 7. Themethod of claim 5 wherein the aqueous system is that of a cooling watersystem.
 8. The method of claim 5 wherein the aqueous system is that of apulp and paper mill system.